Abstract: The validity of the application of energy flow analysis for beam
structures under random excitations is investigated in this paper. The
approximate solutions of energy density and intensity in a beam subject to
random loadings are obtained by solving the governing equation of random energy
flow analysis using Fourier transform technique. The formulations of the exact
energy density distribution and intensity in the beam are derived using the
classical modal analysis method. For a simply supported beam subject to
distributed or concentrated random excitations, the validity of random energy
flow analysis is investigated through comparisons between solutions obtained
from the approximate and exact methods for energy response as well as
intensity. The results indicate that, the mode count of the analysis frequency
band, which means the number of modes involved in the band, is the key factor
affecting the prediction accuracy of random energy flow analysis, and that if
the mode count of the band is sufficiently large, random energy flow analysis
can provide rather accurate estimates for both energy density and intensity in
a wide frequency range.
Keywords: Random energy flow analysis (random EFA), random excitation, energy density, intensity, beam structure
